You didn't say which engine you have, the larger engine is easy, I'd say about 2 hrs labor plus parts which would be $100 to $150.
the smaller 4-cylinder is a lot harder, maybe 3 or 4 hrs. Labor is locally priced so you'll have to make a phone call.
You can try our estimator link:
https://repairpal.com/estimator?car_type_id=2289
If you want to find a specialist, here's a directory link for you:
https://repairpal.com/directory?address=60438&car_brand_names=Oldsmobile

I have a 6 cylinder engine. The estimate price I was given to replace the intake gasket (the intake gasket and vacuum manifold have given me trouble for the life of the car), and the water pump including labor was around $900. I have checked your specialist and they say approximately $860 on the high end. I was given a list of all of the things that could be done -- however, the Olds cutlass has 130+, and I'm hoping to buy a new Toyota Camry in the fall or spring, I don't want to put alot of money into it. The body and interior are in great shape; Ive taken really good care of it in terms of maintenance.
Thanks for your response. I appreciate it.
Bertie